Devices and methods of making devices having one or more components made
of single crystal shape memory alloy capable of large recoverable
distortions, defined herein as "hyperelastic" SMA. Recoverable Strains
are as large as 9 percent, and in special circumstances as large as 22
percent. Hyperelastic SMAs exhibit no creep or gradual change during
repeated cycling because there are no crystal boundaries. Hyperelastic
properties are inherent in the single crystal as formed: no cold work or
special heat treatment is necessary. Alloy components are Cu--Al--X where
X may be Ni, Fe, Co, Mn. Single crystals are pulled from melt as in the
Stepanov method and quenched by rapid cooling to prevent selective
precipitation of individual elemental components. Conventional methods of
finishing are used: milling, turning, electro-discharge machining,
abrasion. Fields of application include aerospace, military, automotive,
medical devices, microelectronics, and consumer products.